Combined type heat-insulating baffle for increasing monocrystal solidification temperature gradient

Abstract

The invention relates to a combined type heat-insulating baffle which is applied to directional solidification equipment and is used for increasing monocrystal solidification temperature gradient. The combined type heat-insulating baffle comprises graphite rings and a flexible graphite felt, wherein the graphite rings and the flexible graphite felt are combined into an annular body, the inner diameter of which is more than the outer diameter of a shell mould to be cast; and the graphite rings are divided into two layers, the upper-layer graphite ring is directly placed on a water cooling sleeve in a directional solidification furnace, the flexible graphite felt is filled between the two layers of graphite ring, a height difference exists between the height of the inner diameter of the upper-layer graphite ring and the height of the outer diameter of the upper-layer graphite ring, and the height from the inner diameter to the outer diameter is increased in a smooth transition manner. The combined type graphite high-temperature heat-insulating baffle disclosed by the invention is convenient to manufacture by just clipping the flexible graphite felt according to dimensions and placing the clipped flexible graphite felt on the graphite rings on the water cooling sleeve as well as directly placing the second-layer graphite ring on the graphite felt, no bolts and nuts are needed for fixation, the placement is convenient and the price cost is low. Compared with the prior art in which a hard graphite felt is used as the heat-insulating baffle, the combined type heat-insulating baffle has the advantage that the temperature gradient is increased by almost 50%.

Description

technical field

[0001] The invention relates to a composite heat-insulating baffle for increasing the solidification temperature gradient of a single crystal, which is applied to directional solidification equipment. Background technique

[0002] Single crystal superalloys are one of the most important key materials for aero-engines. Since the 1980s, the single crystal superalloy technology for turbine blades has been a very important key technology for the development of aero-engines and weaponry. At present, single crystal test rods and blades are mainly obtained by the rapid solidification method (HRS). The process parameters of directional solidification technology include the temperature gradient G of the liquid phase at the front of the solid-liquid interface during the solidification process. L And the solid-liquid interface moves forward with speed R. G L The / R value is an important criterion for controlling the stability of the single crystal growth interface. ...

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